In various types of environments comprising electrical equipment or wherein electrical apparatus are otherwise employed, interconnections of electrical components to incoming utility power are typically provided by means of cables or wires. For example, in office systems comprising modular furniture components, it is often necessary to provide electrical interconnections between incoming power supplies and various types of electrical devices typically used in an office environment, such as electric typewriters, lamps, etc. Computer-related devices, such as video display terminals and similar peripherals, are also now commonly employed in various office and industrial environments.
One advantage inherent in modular office systems is the capability to rearrange furniture components as necessitated by changes in space requirements, resulting from chnnges in the number of personnel and other business-related considerations. However, these modular systems must not only allow for change in furniture configurations, but also must provide for convenient interconnection of electrical devices to utility power regardless of the spacial configuration of the modular systems and resultant variable distances between electrical devices.
In providing the interconnection of electrical apparatus and power inputs, it is necessary to include an arrangement for feeding the incoming utility power to the power outlets. In stationary structures such as conventional industrial buildings and the like, a substantial amount of room would normally exist behind stationary walls and other areas in which to provide the requisite cabling for interconnecting incoming utility power to electrical receptacles mounted in the walls. Such systems, however, could be designed so as to remain stationary throughout their lifetime, without requiring general changes in the office or industrial environment areas.
Systems such as those described above for stationary office building walls typically utilized rigid cables which would extend from utility power inputs to the rear portion of electrical receptacle boxes mounted in the walls. However, in electrical systems for use in environments such as modular office arrangements, there is often relatively little room for extending the cables between utility power inputs and electrical receptacles mounted in the modular wall panels. In addition, because of the capability of the modular systems to be arranged in various configurations, incoming power for one configuration may require a utility power cable extending into the electrical receptacle area from one direction, while other configurations would require the utility power input cable to extend toward the electrical receptacle area from another direction. In such event, different types of power feed connector arrangements would be required.
Still further, as modular office systems are rearranged and distances between electrical devices, receptacles and power inlets are varied, the lengths of interconnecting conduits or cables should preferably be adjusted. Otherwise, connector connections can be difficult to make, and extra (and relatively expensive) conduit or cable may be wasted. In addition, when cable connections are being assembled behind panel walls or the like, space may be severely limited.
Another problem associated with any type of connector arrangement associated with providing utility power to conventional power outlets relates to issues of safety. When utility power connections are to be made to power outlets, it is of substantial importance that the connections be properly made. For this reason, it is preferable to utilize power connection arrangements which, to the greatest extent possible, are configured in a manner so as to substantially prevent the electrician or other craftsperson from making an improper connection. Still further, a primary problem associated with the interconnection of utility power to electrical receptacles relates to the fact that the interconnection at the electrical receptacle may have terminals which are "live" with utility power. To the extent possible, it is therefore preferable to prevent the electrician from coming into contact with such live terminals.
Several types of contact devices are known for use with different types of electrical connectors. For example, Swiss Patent Document No. 648,698 describes a supply plug having a rotatable cable entry hood. The plug includes a cup-shaped molding having guides for three plug pins. An internal cap covers the pin terminals, and an outer shell has a cable anchor point and space for buckles of cable wires.
The internal cap includes a central turret having a central threaded bore. A screw connects the plug cableshell to the turret, while allowing rotation of the shell by 270.degree.in either direction. Holes in the cap allow the passage of the wires from the cable to the terminals. The lengths of the wires allow sufficient play to accommodate shell rotation.
In the U.S. patent to Lenkey 3,754,205 issued Aug. 21, 1973, a connector plug is disclosed having a hollow open-end housing. The open-end is closed by a single slidable sheath surrounding both contact blades of the plug. The sheath includes detents to engage a stop in the housing to retain the sheath and the housing. The sheath is slidable and spring-loaded so that pressure applied to the sheath will cause the sheath to extend inwardly into the housing so as to expose the contact blades.
In the U.S. patent to Wooten 4,445,739 issued May 1, 1984, two embodiments of an arrangement similar to the arrangement shown in the Lenkey patent are disclosed. A male plug arrangement includes a slidable sleeve normally enclosing the terminals, until the arrangement is pushed against a wall receptacle. When pressure is exerted toward a wall receptacle, the sleeve is retracted so that the terminal ends engage the receptacle. Both the Lenkey and Wooten patents also show embodiments whereby an adaptor can be utilized in conjunction with a standard male plug so as to provide a plug having shielded terminals.
The U.S. patent to Kreinsen 861,468 issued July 30, 1907 describes a contact device for electrical conduits which includes two oppositely arranged contact bolts, with funnel-shaped bores to receive concave-shaped heads of the bolts. A spring holds the contact bolts apart, and allows a plug to make a turning movement corresponding to that of an attached cable. It also permits the plug to be automatically released without damaging any part of the plug in the event that a violent "pull" occurs.
The U.S. patent to Gifford 2,239,846 issued Apr. 29, 1941 describes an electrical connection plug for connecting electrical appliances to floor, wall or ceiling receptacles. It includes an adapter plug for engaging the receptacle, with recesses communicating with the electrical conductors and a spring clamping member on the wire leading to the appliance. It further includes a pair of conductor heads adapted for insertion in the recesses of the adapter for making the connection with the conductors.
In the U.S. patent to Perbal 2,334,436 issued Nov. 16, 1943, a joint is disclosed for electrical fixtures. The joint is in the form of an elbow for connecting adjacent members of a bracket arm. The joint allows universal adjustability of one connected member relative to the other, and is constructed so as to offer frictional resistance to the relative adjustments of the bracket members. The joint is further constructed so as to provide adequate space within the joint for the relatively free extension of electrical conductors through the joint, while preventing any type of frictional rubbing action by the joint body.
The U.S. patent to Finizie 2,511,772 issued June 13, 1950 discloses an electrical connecting device having a pair of fixed engageable enclosed contact terminals. A handle is associated with the main body of the device, and includes a pivot member socketed and moveable within the body. Conductors extend through the handle member and strain-relief passages are provided in the pivot member. The conductors are connected to contact terminals by means of flexible coils located exterior and adjacent to ends of the pivot member and extending to the terminals.
In the U.S. patent to Ferguson 2,570,784 issued Oct. 9, 1951, an adjustable electric plug is disclosed whereby a male plug can be inserted into a conventional power outlet, and then rotated in a plane substantially perpendicular to the plug prongs, thereby reducing wear and tear on the plug and of the wires or cording enclosed. The plug includes a hollow cylindrical body portion, with a shank portion extending radially outward from the cylindrical portion. The shank portion includes a pair of cavities extending longitudinally which communicate with the hollow interior of the cylindrical portion. A rotor is provided within the cylindrical portion, and a pair of longitudinally-spaced annular grooves are provided in the periphery of the rotor. A pair of discs are fixed in the rotor with a periphery of one disc being exposed in each of the grooves. A pickup member is positioned in each of the cavities and extends into brushing engagement with one of the discs. The pickup members have U-shaped configurations and straddle the exposed peripheries of their respective discs. An electrical conductor is connected to the outer end of each of the pickup members, and a pair of prongs project from the rotor parallel to the axis of the rotor, with one prong being connected to each of the discs.
The U.S. patent to Teagno 3,601,746 issued Aug. 24, 1971 describes a two-part connector for making multiple connections to a printed circuit panel with one part mounted in trunnions, and with fork leaf contacts engaging tabs of the other part so that the two parts may be rotated in the manner of a hinge to vary the cable leadout angle. These two parts can be mated or disengaged over a wide range of relative orientation, so as to facilitate connections to spaced boards of a stack or in a low access phase.
The U.S. patent to Boutros et al, 4,432,592 issued Feb. 21, 1984 discloses an electrical connector having a protective hood, with strain-relief elements. The strain-relief elements include a pair of opposing clamping members displaced from an initial cable receiving position to a final cable clamping position. The displacement of the clamping members is effected automatically and simultaneously with assembly of the hood to the connector without the requirement of tools.
In the U.S. patent to Haworth et al, Reissue No. 31,733 reissued Nov. 13, 1984, a portable prefabricated panel is disclosed with a pre-wired power system. The panel includes electrical power blocks disposed adjacent to the opposite lower corners of the panel, with the power blocks connected by electrical cables which extend internally of the panel. When two or more panels are connected together, power is transmitted between each adjacent pair of panels by a flexible electrical connector which plugs into the power blocks of the adjacent connector. The panel includes electrical sockets integrally associated with the panel, with the sockets also associated with the power blocks. The blocks are symmetrical so that the same electrical connections can be made on either side of the panel. A channel-like raceway extends along the bottom edge of the panel for permitting the hidden storage of communication cables. The panel also includes a rectangular frame formed from hollow channel-like members which define an interior path around the complete periphery of the panel to facilitate the feeding of cables and conduits along the vertical or horizontal edges of the panel.
In the U.S. patent to Taylor 1,989,893 issued Feb. 5, 1935, an ignition cable is disclosed having a length of insulated wire, with the wire being of greater length than its insulation and extending beyond the end of the insulation. The extended portions are re-bent toward the opposite end of the wire and against the side of the insulation. A tip at the end of each cable includes an embracing skirt, a disc-shaped cap integral with the skirt, and a pair of annular depressions formed inwardly of the skirt and pressed into the insulation. A laterally extended and outwardly disposed resilient tongue is integral with the skirt between the annular depressions, and the re-bent portion of the wire bears against the cap and underlying one of the annular depressions.
In the U.S. patent to Millhimes et al, 4,593,960 issued June 10, 1986, a power entry connector is disclosed for bringing power to an electrical distribution system mounted in modular wall panels. The power entry connector includes a housing, with elements in the housing to retain contacts having tabs extending outwardly from the housing. A spring mounted cover is provided on the housing, to cover the tabs when the tabs are in a nonoperational state. The cover is slidably moveable to expose the tabs, for purposes of maintaining the tabs in an operational state.
Referring to FIG. 1, reference 10 indicates a power junction box comprising the major part of an electrical distribution system located along raceways adjacent to the lower edge of modular wall panels. The junction box 10 is adapted to receive duplex receptacles, such as the receptacle is, which is adapted to plug into recesses 20 located on each side of the junction box 10. The receptacles are energized by tabs 22 positioned on the receptacles. The tabs 22 enter into the box 10 through slots 24 and engaging sockets on the buss bars located within the junction box.
The electrical system is powered by current which enters from a floor mounted monument (not shown in the drawings of the patent), with the current entering the system through a power entry connector 26. The power entry connector 26 allows energizing or de-energizing of an electrical system within the modular wall panels, by plugging into or withdrawing the connection from a recess 20 within any given box 10.
Referring primarily to FIG. 2 of the patent, the power entry connector 26 includes a housing 28, back plate 30, front plate 32, cover 34, springs 36 and contacts 38.
Referring specifically to the housing 28, the housing 28 includes a back wall 48, side walls 50, 52 and end walls 54, 56. These walls are characterized within the patent as defining a front opening cavity 58. These elements are shown primarily in FIG. 2a of the patent. As also shown in this Figure, a hollow boss 60 is attached to and extends rearwardly from the back wall 48. With respect to FIG. 3, the patent shows a passage 62 which extends through the boss, and provides access to the cavity 58 for the wires 40 of the connector. The arrangement also includes various elements associated with the boss 60 which allows a conduit 44 to be secured to the housing.
With respect to the side walls 50, 52 of the housing 28, a latch 70 is provided on each of the walls. The latches are hinged at one end and are resiliently removable in an arc perpendicular to the plane of the side walls. Each latch includes a hook 72 which faces into the cavity 58. One of the latches is adjacent an end wall 56, while the other latch on the opposite wall is adjacent an opposing end wall 54.
The arrangement also includes a safety stop member 74 which is carried on the side wall 50 adjacent to latch 70. The stop member 74 includes a forwardly facing shoulder 76. In addition, a stability "finger" 77 is located on the free edges of top wall 50 and bottom wall 52.
The arrangement also includes two blocks 78, positioned on each end wall 54, 56, to provide shoulders so as to receive latches 80 located within the recesses 20 on the junction boxes. A third block, indicated by reference 82, provides a fulcrum for purposes of utilizing a tool to release the latch 80. An ear 84 is also positioned on each end wall. The holes through the ears receive screws 85 so as to securely attach the connector 26 to the junction box 10.
Each of the end walls 56 includes a pair of retaining elements 86 which are located adjacent the free edge of each of the walls, and which bracket a finger 88 projecting forwardly from the free edge. An end wall 54 carries a single retaining element 86 which is located adjacent the free edge and above finger 88 located on the edge of the wall. In addition, stop elements 90 are provided on the inside surfaces of each side and end wall. Further, a pair of parallel channels 92, 94 are cut into the inside surface of side wall 50. In addition, a single channel 96 is cut into the inside surface of the side wall 52.
The back plate 30 is illustrated in FIGS. 2, 4 and 5. As shown in FIG. 2, a number of openings extend through the plate 30. Two of the openings are indicated by reference 104, and are counter-bored so as to provide a spring receiving section opening into the front face, with a smaller, pin receiving section opening into the back face. These two openings are located near a diagonally-opposite openings of the plate. A second set of openings, indicated by 106, are also counter-bored in a similar manner.
Two contact passages 108, 110 are located on one side of the plate. The two passages are displaced vertically and horizontally relative to each other. In addition, an additional two contact passages are located toward the other side of the plate. These two passages are positioned one over the other. Each of the four passages includes slot sets along two opposing walls. Each set includes two slots on the same plane and with each slot being in an opposing wall. One set, identified in the patent by numeral 116, extends through the passage. A second set, indicated by numeral 118 in FIG. 4, extends a short distance back into the passage from the plate's front face. The slots are also shown in FIG. 2, with the short or second slots 118 being above the first set of slots 116 and passages 108, 110, and below the first set of passages 112, 114. In addition to the contact passages, two contact channels 120, 122 are positioned on the upper edge of the plate 30. An additional contact channel 124 is positioned on the bottom edge, directly below the passages 112, 114. When the plate 30 is positioned within the housing 28, these channels cooperate with channels 92, 94 and 96 so as to form contact passages.
The back face 102 of the plate 3 is primarily shown in FIG. 2a. Rearwardly projecting walls, indicated by numeral 126, extend the length of the aforedescribed passages and channels, beyond the back face. Rearwardly projecting bars 128 are located around the periphery of the plate, so as to meet the stop elements 90 when the plate 30 is positioned within the housing 28.
The front face 130 of the plate 32 is primarily shown in FIG. 2, with sectional views also shown in FIGS. 3, 6 and 7. A pair of openings 132, located near diagonally opposite corners of the plate 32, extend therethrough. Slits 134 extend through the plate and are positioned to be in line with the slots 118 in the passages in plate 30 when the two plates are positioned together in housing 28. Correspondingly, notches 136, 138 are provided in one edge of the plate near one corner. A single notch 140 is provided in the opposite edge of the plate near a diagonally opposite corner. These notches are in line with channels 120, 122 and 124, respectively, in plate 30 when the two plates are positioned together. A recess 142 is also provided in each of the two elongated edges of the plate.
The cover 34 is primarily shown in FIGS. 1 and 2, and also sectionally illustrated in FIGS. 3, 6 and 7. The cover 34 includes a front wall 144, side walls 146, 148 and end walls 150, 152. A series of slits 156 extend through the front wall and into a cavity 154 formed by the five walls of the cover 34. The slits are in registration with the slits 134, and with notches 136, 140 when the power entry connector is assembled. An additional slit 157, adjacent one of the slits 156 and located next to the side wall 146, is in registration with the notch 138 and channel 122.
Referring to one end of the cover 34, a pair of slits 158 are provided. An additional slit 158 is also provided on the opposite end of the cover. The slits comprise core pin access openings for the purpose cf providing grooves 160 along inside surfaces of the end walls, and a forwardly facing shoulder 162.
In addition to the slits 158, additional slits 164 of somewhat greater width are also provided in the front wall. These slits receive fingers 88 in the housing 28, when the connector is assembled and plugged into the recess 20 within the box 10. Additional slits 165 are also provided in the front wall adjacent side walls 146, 148 so as to receive stabilizing fingers 77. A cutout 166 is also provided in each of the end walls 150, 152.
The arrangement also includes a series of contacts 38 which are stamped and formed from a conductive material. Each of the contacts includes a tab 170. The contacts include "hot", "neutral" , and "ground" wire interconnections. Each of the contacts also includes a pair of laterally projecting ears 176.
The assembly of the power entry connector 26 is primarily illustrated in FIGS. 2 and 3. Specifically, a threaded stud 68 is positioned within the cavity 58 of the housing 28. The conduit connector 44 is secured to the housing 28 with a lock ring 46 threaded onto the stud 68. The contacts 38 are then interconnected with the wires 40 and threaded through the conduit connector and housing 28.
The contacts are then threaded through the appropriate passages and channels within the plate 30. These contacts are passed through various aforedescribed passages, and the back face of the plate 32 is abutted against the front face 100 of the plate 30. Snap pins on the plate 32 are forced through openings 106 for temporarily retaining the contacts between the plates.
With the plates 30 and 32 positioned together, they are then positioned within the housing 28. As the two plates are moved into the cavity 58, the latches 70 are biased until the plate 32 passes behind the hook 72. The latches 70 then snap back to bring the hook in front of the plate 32 and into the recesses 142. In this manner, the latches removably lock the two plates within the housing 28 as primarily shown in FIGS. 6 and 7.
The cover 34 is then added for purposes of completing the assembly. Specifically, the coil springs 36 are located on the pins 168 (as shown in FIG. 6). The sidewalls 146, 148 and end walls 150, 152 slide over the side Walls 50, 52 and end walls 54, 56 of the housing 28. The end walls 150, 152 bow slightly in passing over the retaining elements 86 until the elements 86 enter the grooves 160. The retaining elements, in cooperation with the shoulders 162 defined by the grooves, removally retain the cover on the housing as primarily shown in FIGS. 1, 6 and 7. In this manner, the cover 34 can then be moved back and forth on the housing for the length of the grooves.
The pins 168 slide through the openings 132 and 104. The coil springs 36 are located within the openings 132 and sections 104. The forwardly facing shoulder defined by the counter bores in openings 104 and the inside surface of front wall 144 of the cover capture the coil springs therebetween.
The connector arrangement, without the cable conduit 44 and four of the six wires 40 and associated contacts, is shown in a sectional manner in FIG. 6 in a non-functioning state. That is, the springs 36 urge the cover 34 forwardly away from the housing 28 so that the tabs 170 are isolated by the cover. In this manner, two safety features are provided. Specifically, the stop member 74 is configured so that the cover 34 abuts the shoulder 76, and cannot be moved further rearwardly until the member 74 is depressed. The second safety feature includes cutouts 166. The cutouts 166 provide a recess for blocks 78 as the cover moves back on the housing 28. With the cover in its forwardly extending position as primarily shown in FIG. 1, the cutout space provides an access into the cover cavity 154 and contact tabs 170, except for the forwardly extending fingers 88. These fingers 88 block such an access.
FIG. 7 is a sectional view similar in configuration to FIG. 6. However, in FIG. 7, the connector 26 is shown as if plugged into the recess 20 within the box 10. The connector 26 moves into the recess 20 until the cover 34 encounters a back wall to recess. At that point, assuming that the stop member 74 is depressed, the rest of the connect continues to move forward. The tabs 170 pass through slits 156 and into sockets on the buss bars within the box by means of slots 24. The coil springs 36 are compressed and the free ends of the pins 168 enter the cavity 58 of the housing 28 by means of openings 104. When the connector 26 is fully moved into the recess, the latches 80 are "caught" on the block 78 so as to releasably lock the connector to the box. The connector is then made more secure against an inadvertent withdrawal by securing self-tapping screws 85 into the box 10 through holes in ears 84 in the housing. The holes 178 are provided on the box to receive the screws.
The connector 26 can be released from the junction box 10 by removing the aforementioned screws and prying back the latches 80. For this function, a screwdriver tip or similar tool can be inserted against the latch, and the block 82 utilized as a fulcrum. In this manner, the latch is "pried" off the block 78. Although the Millhimes et al arrangement provides a power entry connection assembly, the arrangement does not appear to provide any facilitation of adjustment of the cable conduit position relative to the power connector and junction box.